Says the girl who never sleeps!
But yeah, sleep is one of those things that are easy to screw up. You have to really be strict with managing your time, and if you stay up too long one night, it can, depending on how you react to the lost sleep you deprived yourself of, lead to a snowball of problems like consuming drinks with caffeine in them to assist in maintaining consciousness that won't get better until you determine to go to bed at X time no matter what, and you get comfortable with that schedule. It requires a lot of motivation to abstain from getting tasks you want to get done finished if you've got a lot you want to get done with your free time, but not a lot of time to yourself to get it done.